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Heuristics that almost always work

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331–340 of 541 posts

Re: Heuristics that almost always work

#331
post #306

"Fifty thousand years ago there were these three guys spread out across the plain and they each heard something rustling in the grass. The first one thought it was a tiger, and he ran like hell, and it was a tiger but the guy got away. The second one thought the rustling was a tiger and he ran like hell, but it was only the wind and his friends all laughed at him for being such a chickenshit. But the third guy though…

Natural selection doesn't always favor the paranoid. Running like hell requires a lot of energy and if we're overly paranoid, we might just run ourselves to death whenever the wind is wilder than usual

Who says humans aren't running ourselves to death at the sound of the wind right now?

Re: Heuristics that almost always work

#332

I read them as sloppy caricatures that provide little value to the conversation. Let's take the security guard: "The only problem is: he now provides literally no value. He’s excluded by fiat the possibility of ever being useful in any way. He could be losslessly replaced by a rock with the words “THERE ARE NO ROBBERS” on it." That is blatantly not true, the guard provide value since the wanna-be robbers don't know w…

The Hydroxychloroquine discussion is pretty bad as well.

We were confidently against Hydroxychloroquine because it was well tested in the RECOVERY trial in June 2020 [1].

The time to be optimistic was during the trial-phase of the test. Once that time passed, everything beyond that point was unnecessary and unhelpful hype.

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What's amazing to me, is that the RECOVERY trials showed that Dexamethasone cut the death rates in half [2]. Where did the Dexamethasone hype go? Why was the political discussion on the snake-oil Hydroxychloroquine?

Even months before we had a vaccine, doctors had discovered how to save roughly 10% of lives in the most severe category. (29.3% death rate vs. 41.4% death rate for those on ventilators). Doctors quickly started using the $20 steroid to save so many lived throughout the pandemic.

Instead of hyping the stuff that _WORKED_, the political system was hyping snake-oil like Hydroxychloroquine and Ivermectin. Why were so many people optimistic on such bullshit?

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Here is where being skeptical helps. Whenever Hydroxychloroquine or Ivermectin came up in a stupid discussion, I'd pivot the discussion towards Dexamethasone and Monoclonal antibodies. People need hope. People want hope. Before we had vaccines, people wanted to know that doctors had an idea of what to do. Dexamethasone and Monoclonal Antibodies did the job and did it properly (saving lives long before vaccines were developed). No one cared if it was "hydroxychloroquine" or "dexamethasone", these are all just giant chemical that few people memorize. People wanted hope, and it was important we kept that hope factually correct.

You can't promise the world with bullshit snake oil. When someone gets COVID19, they'll demand Ivermectin (yes, my sister is a doctor and she's seeing patients who are literally dying and demanding Ivermectin from her). Ivermectin has given these people false hope and is turning them away from the actual care that would save them.

[1]: https://www.recoverytrial.net/news/statement-from-the-chief-...

[2]https://www.nejm.org/doi/full/10.1056/nejmoa2021436

Re: Heuristics that almost always work

#333

I read them as sloppy caricatures that provide little value to the conversation. Let's take the security guard: "The only problem is: he now provides literally no value. He’s excluded by fiat the possibility of ever being useful in any way. He could be losslessly replaced by a rock with the words “THERE ARE NO ROBBERS” on it." That is blatantly not true, the guard provide value since the wanna-be robbers don't know w…

At least in the case of the doctor, the numbers are also way off. A typical doctor sees thousands, if not tens of thousands of patients in their career. This would certainly translate to _way_ more than two or three misdiagnosed cancers.

Re: Heuristics that almost always work

#335

Earlier quoted context omitted.

The "slippery slope" principle applies here though: N+1 enables N+2, which enables N+3 and so on.

but the risk is independent. so once you do the N+1 time safely, you are back to N and your next time is _also_ just an N+1.

Yes, but when you make a plan to find an acceptable cumulative future risk, planning to do it once a week for the rest of your life is planning to expose yourself to significantly more risk than doing it twice a year for the rest of your life.

You might still die in one of the next 20 instances. But you've added a lot more not-dead time in between them!

Saying "I can do one more with minimal added risk" every single time after not dying is true and yet pointless, because it's not a given that "minimal added risk" = "not dying." It's survivorship bias to not think frequency doesn't affect the cumulative odds of your future planning solely because you've already done a lot of trials.

Re: Heuristics that almost always work

#336
post #198
post #170

Earlier quoted context omitted.

That only applies if you are updating priors. In this case the odds are fixed, the GP is correct.

The odds of a rocking accident are known and fixed?

Probably not. But they aren't affected by the previous N climbs, at least as described by GP post. They are considering a fixed odds event, and the probability of (bad thing happens) over a sample path through time. That's not the turkey fallacy.

In other words , the difference between the turkey and the climber is the climber knows the odds (at least nominally) , and it’s important .

Re: Heuristics that almost always work

#337

"Fifty thousand years ago there were these three guys spread out across the plain and they each heard something rustling in the grass. The first one thought it was a tiger, and he ran like hell, and it was a tiger but the guy got away. The second one thought the rustling was a tiger and he ran like hell, but it was only the wind and his friends all laughed at him for being such a chickenshit. But the third guy though…

The parable of tigers in the grass might demonstrate a selective pressure towards caution, but doesn’t demonstrate any benefit towards ascribing agency to natural phenomenon.

The agency of the entity which caused the rustling is somewhat irrelevant for the hunters. The important belief for their survival is that this rustling entity is dangerous. If they hold this belief but attribute the behaviour of the entity to randomness, they’ll do just as well.

Re: Heuristics that almost always work

#338
post #87

This story reminded me of a story written by a Czech biologist who studied animals in Papua-New Guinea and went to a hunt with a group of local tribesmen. The dusk was approaching, they were still in the forest and he proposed that they could sleep under a tree. The hunters were adamant in their refusal: no, this is dangerous, a tree might fall on you in your sleep and kill you . He relented, but silently considered…

Is 1:5000 an actually good assessment? I'd suspect it's very much not, especially if you avoid obviously dead trees and maybe move if a storm comes.

PNG has a lot of eucalyptus trees, and some species drop their branches with zero warning, which originated as a mechanism for surviving droughts. I don't know enough to tell whether that's what's going on in the estimate.

Re: Heuristics that almost always work

#339

I read them as sloppy caricatures that provide little value to the conversation. Let's take the security guard: "The only problem is: he now provides literally no value. He’s excluded by fiat the possibility of ever being useful in any way. He could be losslessly replaced by a rock with the words “THERE ARE NO ROBBERS” on it." That is blatantly not true, the guard provide value since the wanna-be robbers don't know w…

I agree with you. The value of the heuristic is in the 99.9% and the value of the person is in the 0.01%. That's why doctors are so valuable. It's for those times when someone comes back and says, "It didn't work." If we waste the doctor's time on the 99.9%, then they lose their primary function of being the expert during the unexpected. For an individual, they may seem interchangeable with a rock, but for a society,…

> If we waste the doctor's time on the 99.9%, then they lose their primary function of being the expert during the unexpected.

I don't agree that this is a waste of time. The reason why we go to the doctor when we have unusual pains and aches is because we are not qualified to decide whether it's a minor annoyance or a symptom of a life-altering problem. We're seeking out an expert to help make that determination.

If two people could walk in with the same described symptoms, but one just ate something that disagreed with them, and the other has stomach cancer, then doctors must do at least a basic diagnostic exam on the spot, and not turn the patient away for days or weeks to see if the problem goes away on its own. This isn't a "waste" of time at all.

I just saw a PA a couple weeks ago about a knee injury. The end result was that she did tell me to take ibuprofen for a few weeks and then report in how it feels. But, before that, she spent a good 20 minutes asking about the history of the injury, and then felt around to see if there was anything noticeably wrong. And after that she gave me an idea of what the next steps would be if it doesn't get better on its own. The entire experience gave me confidence that she was attentive to what I had to say, knew what she was talking about, and had a plan in case things don't get better.

If she had merely listened to me for 5 minutes, and then told me to take ibuprofen for a few weeks and call back if it's not better, and that was it, I would not have felt good about that encounter, and would have gotten a second opinion from another doctor.

Of course, this also raises the question of whether or not doctors who put in that bare-minimum, insufficient amount of effort (as described in the article) actually are common. I really hope they aren't! But maybe they are, I dunno. The author is a medical professional (albeit on the mental health side), so I would expect he'd have a better idea of how common that is than I do.

Re: Heuristics that almost always work

#340
post #267
post #179

Earlier quoted context omitted.

Reminds me of the fact that on overage, one out of every hundred places you know will be experiencing a once-in-a-hundred-years event. When you hear once-in-a-hundred-year event, it makes it sound quite rare. One might look around and say (for example, in relation to climate) "why are so many of these happening?" But it is unsurprising statistically. If you know just a thousand distinct geographic places, about 10 of…

There's something intuitively misleading here, though I'm not sure what it is. I am looking at 100 square inches of floor right now and nothing unusual is happening in any of them.

Are there 100-year events associated with 100 square-inch plots of floor? No... But there are with coastlines, cities, dams, forests, deserts, islands, volcanoes, etc.

Of course there are other compounding factors. Not all events are one-in-one-hundred; some are one-in-ten, others are one-in-five-hundred, and with increasing scarcity by order of magnitude.

Another compounding factor is that the borders for "geographical areas" are fuzzy. Does a one-in-a-hundred year event that happens in Vermont also qualify as having happened in New Hampshire? Probably depends on the type and the specific measurements and the expectation according to history.

And what about aggregate events? E.g. "It's been five hundred years since we've seen this many tornadoes, which tend to happen once every ten years."

And in the opposite direction of the 100 square-inch plot of ground, there is blurring in the other direction: What do they mean in aggregate if they are fewer than expected at a global scale?

So my original comment was just a simple way of taking the average of all of these competing factors and stating a general truth that's somewhere in the middle. If you have X things that are expected to have 1/Y probabilities, then the probability of you experiencing any of them is not 1/Y, it's more like X/Y. (As in very likely.. that's more than 1 so obviously not mathematically correct.) But we often don't think about rare events this way - as no specific event being probable, but some collection of improbable events being almost certain. We perceive them all as 1/Y. It's just a very local way of thinking.

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